title: Obsessive-compulsive disorder; chronic versus non-chronic symptoms.
abstract: OBJECTIVE
  Understanding chronicity in OCD is hampered by contradictory findings arising from dissimilar definitions of chronic OCD. The purpose of this study was to investigate the magnitude of chronicity in OCD and to examine if chronic OCD is critically different from non-chronic OCD, using a chronicity definition that reflects empirical findings.
  
  
  METHODS
  Baseline data of the Netherlands Obsessive Compulsive Disorder Association (NOCDA) study, in which 379 OCD patients participated, were analyzed. Chronic OCD was defined as "continuous presence of at least moderately severe OCD symptoms during at least two years", and was assessed retrospectively using a Life-Chart Interview.
  
  
  RESULTS
  Application of the chronicity criterion resulted in two groups with highly distinguishable course patterns. The majority of the sample (61.7%) reported a chronic course. Patients with a chronic course reported significantly more severe OCD symptoms, more illness burden, more comorbidity, an earlier OCD onset and more contamination and washing - and symmetry and ordering symptoms. Multivariable logistic regression analysis revealed that chronic OCD was independently associated with more OCD-subtypes (p<0.001), contamination and washing symptoms (p<0.001), earlier OCD onset (p=0.05) and higher severity of compulsions (p<.01).
  
  
  CONCLUSIONS
  The findings are based on a cross-sectional survey. Furthermore course was assessed retrospectively, implying the possibility of overestimation of persistence and severity of symptoms.
  
  
  CONCLUSIONS
  Chronicity is the rule rather than the exception in OCD in clinical samples. Chronic OCD is critically different from non-chronic OCD. Further attempts to break down the heterogeneity of OCD in homogeneous course subtypes should be made to allow for a more precise determination of the pathogenesis of OCD and better treatment.
authors.affiliation: Innova Research Centre, Mental Health Care Institute GGZ Centraal, Ermelo, The Netherlands. Electronic address: h.visser1@ggzcentraal.nl.
authors.forename: Henny A
authors.initials: HA
authors.lastname: Visser
authors.forename: Patricia
authors.initials: P
authors.lastname: van Oppen
authors.forename: Harold J
authors.initials: HJ
authors.lastname: van Megen
authors.forename: Merijn
authors.initials: M
authors.lastname: Eikelenboom
authors.forename: Anton J
authors.initials: AJ
authors.lastname: van Balkom
mesh_terms: D000328:Adult; D002908:Chronic Disease / Q000523:psychology; D015897:Comorbidity; D017281:Cost of Illness; D005260:Female; D006801:Humans; D007406:Interview, Psychological; D016015:Logistic Models; D008297:Male; D009771:Obsessive-Compulsive Disorder / Q000145:classification / Q000453:epidemiology / Q000523:psychology*; D011569:Psychiatric Status Rating Scales; D011788:Quality of Life / Q000523:psychology; D012189:Retrospective Studies; D012720:Severity of Illness Index
keywords: Age at onset; Chronic disease; Obsessive-compulsive disorder; Severity of illness